What product does everyone use when spraying the intake checking for leaks?

[Ski 61701]

Unlit propane torch

 

[dvw]

Propane was actually a factory recommended method at one time
Doug

 

[Ranger16]

Brakleen, TB cleaner, propane, whichever is closest.

 

[PurpleBeeper]

For simply confirming a leak, and better than any spraying of stuff IMO, is simply putting your hand over the carb.

True, hand over the carb tells you if you are super-lean which is usually a vacuum leak, but unfortunately it doesn't tell you exactly where the leak is.

 

[BSB67]

True, hand over the carb tells you if you are super-lean which is usually a vacuum leak, but unfortunately it doesn't tell you exactly where the leak is.

I have never had a carburetor gasket leak, ever. Probably snitched carbs 50 times. Next is an open vacuum port, leaking vacuum line. Pretty easy to find those. Finally, and the one that I find to be the case more that anything, intake gasket. More often than not, you cannot find the intake leak with flammable aerosols.

 

[PurpleBeeper]

I have never had a carburetor gasket leak, ever. Probably snitched carbs 50 times. Next is an open vacuum port, leaking vacuum line. Pretty easy to find those. Finally, and the one that I find to be the case more that anything, intake gasket. More often than not, you cannot find the intake leak with flammable aerosols.

Well, I think you can find intake leaks ON TOP, but underneath is a whole other story. I'm about to go hunting for what I "suspect" is an intake leak on the bottom of the intake in the next couple of weeks using a method someone here showed me on the Hughes site.... PIA, but it should tell me for sure if my intake is square.

 

[BSB67]

Well, I think you can find intake leaks ON TOP, but underneath is a whole other story. I'm about to go hunting for what I "suspect" is an intake leak on the bottom of the intake in the next couple of weeks using a method someone here showed me on the Hughes site.... PIA, but it should tell me for sure if my intake is square.

.........And, every intake leak that I have found has always been on the bottom.

 

[dual fours]

Used Ether spray back in the day in the Army....

I think all I had was Ether (starting fluid), it worked for me, and it works great to seat a bead on a tire.

 

[Joeyt66]

It the years past I've used ether, carb cleaner. But before I retired I had good luck with propane. Just be careful of a spark !

 

[That_Tall_Dude]

I read a forum post like 10 or 15 years ago somewhere; dude a had a huge vacuum leak but it couldn’t be detected with liquid sprays; it didn’t have enough velocity to pull it in.

Was like 1/16” gap or something on the underside of the intake (when it was cranked down) on both sides for the full length of the block. I think he used epoxy to address it.

He did compression testing to find it: flat metal plate with a fitting/gauge where the carb sat and loosened the rockers so all the valves close; I bet the propane might of found it, never heard of it before

Was going to do the compression version but might try propane...